Paper cup and blank therefor



Feb 10,1942. I GaAMBERG 2,272,499

PAPER CUP AND BLANK THEREFOR Original Filed May 6, 1939'V/////////////J\\ INVENTOK ATTORNEY.

Patented Feb. 10, 1942 UNITED STATES PATENT OFFICE Y Ralph G. Amberg,Llbertyvilie, 11]., assignor to Universal Paper Products Company,Chicago, 111., a corporation of Illinois Original application May 6,1939, Serial No. 272,080. Divided and this application October 14, 1939,Serial No. 299,497

(Cl. 229-15) p 7 States Patent No. 2,139,614, that a continuous 6Claims.

concerned with the production of an improved type of cup by a new andimproved method by which the cup is formed from a continuous strip ofpaper.

The type of cup described in the aforementioned patents is madepractically entirely without waste, and therefore, it is one of the mosteconomical cups ever developed. An important feature of the manufactureof this cup; as

pointed out in United States Patents Nos.

2,139,613 and 2,139,615, resides in the fact that the cup is formed froma continuous strip of paper. Usually cone-shaped paper cups having =apointed apex are made by forming initially a paper blank andsubsequently rolling or winding the blank thus formed into a conicalvessel. In

most instances it has been necessary to die-cut.

blanks from paper and stack them one upon another in a magazine fromwhich they are fed singly to a pair of cup forming cones.

In other instances it has been proposed to cut the blanks from acontinuousstrip of paper or web and to feed the blanks thus out siriglyone by one to cup forming cones. In all of these instances it has beencustomary to have a certain amount of waste which is produced during thedie cutting, the blank forming or the-cup forming operations. In thefirst of these instances the waste results from'the paper betweenadjacent die cuts, in the second, by the paper which is disposed betweenadjacent cup blanks and is rejected as surplusage, and in the third bythe excess paper-which is trimmedfrom the blank by means of a knifeengaging with the base of one of the cones.

In making paper cups of the type covered by.

the patents previously mentioned and according to the methods describedtherein, all waste may be eliminated and at the same time every portionof the paper is used in forming and reinforcing the cup. For convenienceit is sometimes desirable to cut ofi sharp ends of the paper strip priorto or during the'cup forming operation but I apex becomes extremelyimportant.

strip of material adapted to be formed into a series of cups insuccession is advanced to a forming mandrel in such a way that theforming operation begins in proximity to the leading edge of thematerial or more specifically, at the center serves as a pad or presserplate during the operation of forming the cup. Each time the mandrelrotates in its orbit a cup is formed and discharged and at the time themandrel discharges the cup, the paper strip advances again to be inposition for another forming operation. When it is realized that thiscup forming operation may take place at speeds from to 250 cups perminute, or even higher, it will at once be understood that the problemof properly forming the Various types of instrumentalities may be usedto feed the paper strip to the forming cone, the feed being eithercontinuous or intermittent. Many types of devices may be employed toassist the feeding operation. Likewise, a number of difierent devicesmay be employed to assist the formation of the apex of the cone, butfrom every standpoint it is desirable to have the machine as simple aspossible. At the same time it is desirable to form the cups in such away.

that leakage is practically out of the question.

With the foregoing considerations in mind, one of the objects of thepresent invention has been to provide a new and improved type of papercup having a leakproof apex.

Another object has been to provide a paper ,cup of the characterdescribed in which the apex is formed accurately, conveniently andsimply.

Still a further object is to provide a method of forming paper cupshaving an improved leakproof apex which is extremely simple in operationand simplifies rather than complicates the cup forming machine. Otherobjects will appear hereinafter.

According to this invention it has been found that in making cone-shapedcups having an apex the apex is capable of remaining leakproof even whena liquid is allowed to stand in the cup over along period of time. Thisis particularly true, for example, of cups which are used as soda cups,although the accuracy with which the apex is formed is also important inconnection with ordinary drinking cups.

The method involved is particularly well adapted for use in connectionwith the formation of cone-shaped cups having a pointed apex where astrip of material from a continuous roll is advanced to a conical formerin such a manner that the forming operation begins from the leading edgeof said material. According to this invention the strip of material maybe partially severed at intervals throughout its length so that as itadvances into the orbit of a mandrel rotating around its axis and alsoin a circular path against a smooth fixed surface the mandrel beingequipped with a cutting edge severs the strip transversely along a lineof severance which intersects the previously severed slits and therebyforms a slit in the leading edge for the next cup forming operation.

The slit thus formed in the forward edge of the strip of paper isusually spaced a. substantial distance from the apex of the cup or thecenter of the mandrel orbit and is on that side of the apex from whencethe cup forming operation is begun. The mandrel is provided with meansfor holding the paper against it as it rotates in contact therewith.Thus, according to a preferred method of operation, as a. cone-shapedmandrel rotates about its own axis and in an orbital path, it picks upthe leading edge of the paper, thereby beginning to wind the paper intothe form of a cone. As the winding operation continues the cutting edgeof the mandrel severs the paper along a path transversely of thelongitudinal axis of the paper. The gripping means whereby thepaper isgripped to the mandrel is normally placed adjacent the base orouter'portion of the mandrel. During the initial stages of the windingoperation the portion of the paper adjacent the grip ping means will beheld closely against the mandrel but the slit in the leading edge of thepaper causes that portion of the paper adjacent the slit andparticularly that portion of the paper between the slit and the apexpoint to fly outward and be more or less free from the mandrel. Prior toor during the forming operation an adhesive is applied to a face portionof the paper strip which is ultimately to form an overlap or seam in thefinished cup. The face of the free portion or flap on the leading edgeof the strip caused by the slit isbrought into contact with thisadhesive as the mandrel continues to roll in its orbit and thus, firmlyseals the flap in an area adjacent the apex portion of the cup, therebyforming a glued flap of material at the apex. At the same time a reversecrease is formed between the interior point at which the slit terminatesand the apex point. This flap of material and without the necessity forusing any other instrumentalities whatsoever. The speed of operation isnot decreased. Furthermore, by using a method of this type it has beenfound that certain devices heretofore employed to assist the advancementof the paper can be discarded, thus simplifying the machine anddecreasing the cost of operation.

Other features and advantages of the invention will become apparent froma reading of the following specification in the light of theaccompanying drawing. in which:

Figure l isa top plan view illustrating somewhat diagrammatically themethod of the present invention;

FigureZ is a view of the cup being wound upon the former of Figure 1;

Figure 3 is an enlarged cross-sectional view taken through line 3-3 ofFigure 2;

Figure 4 is a view in section of the cup former and cutting knife;

Figure 5 is a side elevational view of the completed cup;

Figure 6 is a plan view of the cup shown in Figure 5;

Figures 7 and 8 are views in section taken through 1-! and 8-8 of Figure5, respectively;

Figure 9 is a plan view of the apex portion of the cup unwound to showthe position of the creases and slit;.

Figure 10 is a view in perspective of the apex of the cup partiallyformed as in Figure 2; and

Figure 11 shows a modified form of blank.

becomes enveloped by the overlap as the rotation this invention is tobefound in the fact that the whole operation of sealing the apex in themanner described is accomplished by forming a slit in a paper strip atpredetermined intervals In the drawing the machine .and method arepurposely shown somewhat diagrammatically. The actual machines whichhave been constructed to embody the present invention contain manydetails of design and construction which are subject to much variationand which although useful are not considered patentable and hence, arenot being disclosed or claimedherein. On the contrary, only the basicimportant and broadly novel features of the invention are disclosed andclaimed in order that the importance of such features will not beobscured or overshadowed by the inclusion of mere details of feedingmechanisms, gluing devices, gear arrangements, supports, stackers andthe like. All of these latter named instrumentalities are old and existin many diflerent forms so that any mechanic skilled in the art canquickly and conveniently adopt and adapt them for the practice of thisinvention.

Turning now to Figure 1, a continuous strip of paper l0 coming from aroll or other suitable source of supply is fed by a suitable mechanismto a forming cone 12. In actual operation the forward or breast edge Hof the paper strip is fed into the position illustrated in Figure 1 inwhich apex point IS in proximity to the center of edge l4 coincides withthe apex of the former l2 and when it reaches this point the formerrolling over the end of the paper strip causes further feed of the paperto be temporarily suspended while a cup rolling or winding operationtakes place.

The conical cup former I2 rotates about its own axis and simultaneouslymoves through a circular orbit of which, in the construction illustratedin Figure l, the axis of the cone forms the eenter. In the positionillustrated a mechanical lawn or clamp l8, known in the art as a"pick-up," engages the forward extremity 20 of the paper strip and asthe mandrel continues to rotate and movebodily in its circular path, the

' cone l2.

, paper strip and continues until the formation of the cup is complete.To prevent the continuous strip 10 from being torn and twisted it isnecessary to sever the cup from the end of the strip and this is donesimultaneously with the cup forming operation.

As shown in Figure 4, the rear edge 22 of conical former I2 is sharpenedto serve as a cutting edge and it cooperates with a cutting edge 24formedon the forward extremity of a platform 26 across the upper surfaceof which paper strip I0 is fed. The contour of cutting edge 22 isarouoperation about the table or smooth surface lupon which the coneshaped former I2 is mounted. As the cup is completed it is stripped fromconical former l2 by any convenient stripping device such as compressedair, a movable 'tip or plunger forming th apex of th conical former, ora stripping wheel which engages the exterior of the cup. The glue linesa, b and 0 may be applied to the paper strip at any convenient pointwith any suitable type of gluing mechanism such. as applicator rolls.

The essential feature of the present invention resides in the provisionof the slits 28, 30, 32 and 34 at predetermined intervals in paper stripID, as shown in Figure 1. These slits are so-placed that they intersectthe line of severance of cuttingedge 22 with paper strip 10. Thus, asshown in Figure 2, when mandrel l2 has partially completed its orbitalpath and has partially formed a paper cup, slit 28 has caused a portion36 of the leading edge of the paper .to separate fromthe body of thepaper cup and extend outwardly. This outwardly extending portion or flap36 .becomes sealed by means of glue line 0 across the upper face of thepaper and is thereafter over-- lapped by overlapping portion 38, wherebythe flap 36'is sealed within the overlapped seam. It will be observedthat the winding operation causes a reverse crease 50 to be formedbetween the apex point and the innermost extremity of the slit, as shownin Figures 3, 9 and 10. By a revers creas is meant a crease in which theface of the flap is bent backward or reversed with respect to the faceof the strip. A regular crease 40 is also formed.

It is practically impossible for a cup made in this manner to leak. Thesealing of the flap to the face of the overlap is in itself suflicientto seal the apex and the further sealing of the flap into the seamprevents any possibility of leakthe centers of radius of curvature ofthe arcs along which the strip is transversely severed. Thus, point 16which forms the apex of the cup, falls on line A-A andthe correspondingpoint in each succeeding cup will also fall on line A-A.

It is not essential, however, that the line A-A correspond to thecentral axis of the strip, nor that the shape of the blank which isultimately to be formed be exactly as shown in Figure 1. For instance,the edge of the strip at which the forming operation is started maycorrespond to line BB, the other edge remaining just as shown in Figure1, or the edge of the strip may correspond to the line C C onthe otherside. In either vent, the longitudinal axis AA would be to one side ofthe center of the strip. Where it is desired to have'a cup of doublethickness throughout the area adjacent the mouth of the cup, this can beaccomplished by extending the width of the paper so that one edgecorresponds to the line C--C and the other to'the line 3-3. If a cupwere to be unrolled after it has been formed, as described in Figure 1,it would be found that th shape is that of a four-sided figure, twosides being curved and two sides straight, whereas, if either edge ofthe paper is extended to the line C--C or to the line BB, but not both,the shape of the figure from which the cup is formed would be athree-sided figure.

two sides curved and one straight, and if both edges are extended tolines 0-0 and BB, the

- cut or other line of severance.

age either from cracking of the paper at the apex or otherwise.

. As shown in Figure 1, the glue line 0 may be partially offset at point42 in order that no glue comes into contact with the interior of thecup. This offset should be large enough to take care order to add to theattractiveness of the cup,.th ends of the paper at points M and 46 maybe severed in any suitable manner, .thus'producing an efiect as shown inFigure 5. It will be ob 'Of the space created by pocket portion 36. In

served that in Figure 5 that part of the leading edge of the stripbetween point 44. and slit 28 is 7 tralaxis of th strip and is also aline joining shape of the cup is a two-sided figure with both sidescurved. The shape ofthe material from which the cup is formed ispreferably such that opposite sides have the same radius of curvature,one of said sides being convex and. the other concave with the concaveside containing a slit,

It will be understood, however, that the invention, in its broaderaspects, is not limited to the formation of cups of this particulartype: For example, a similar cut or slit may be-made in th lower edge ofthe rectangular blank shown in United States- Patent No. 1,434,934,granted to Van Sant Novena-- ber '7, 1922.

The slit, cut or other line of severance on the forward edge preferablyextends in a longitudinal direction with respect to the paper strip,although it may extend in other directions just so long as the effect ofthe slit during the forming operationis to permit a portion of theforward edge to separate in such a manner that the separated portionv orflap is sealed face to face against an overlapping portionof the paperin the manner previously described.

The slit or partial severance of the paper strip as described inaccordance with this invention may be at different points on'the leadingedge, or in that portion of the paper which is ultimately to become theleading edge. This will vary some-" what depending upon the desired sizeof the pocket portion at the apex of the cup and the size is controlledby the depth of the slit and by its distance from the apex point of thecup. Naturally with a larger sized cup a larger slit and a larger sizedsealed flap portion may be formed adjacent the apex. The slit need notbe severed in. a single line but may be wedgeshaped or any otherconvenient shape. For example, as shown in Figure 11, the cut or severedportion 28in the forward edge of the blank may have a rounded innerextremity to prevent tearing with certain types of paper when the cup iswound. For a similar purpose and to otherwise assist the formation ofthe crease, the table or surface upon which the cone-shaped former ismounted may be provided with a slightly raised portion where the reversecrease is to be formed designed to complementally fit into and coincidewith a hollow or dished out portion on the face of former l2, not shown.Many other variations may be made in the method described withoutdeparting from the invention.

Thi invention makes it possible to form with great rapidity a new andimproved type of paper cup which is leakproof in every respect. Aspreviously indicated, this type of cup is especially useful in thelarger sizes of cups such as are employed as soda cups. In this type ofcup the tendency to leak is unusually great because it is oftencustomary to allow liquids to stand in such cups overa long period oftime. In many instances special glues are required in order to keep acup of this type from springing a leak at the seams but in a cup madeaccording to the present invehtion, the ordinary types of glues employedin the manufacture of paper cups may be used. It will be appreciatedthat this .type of cup is extremely economical to manufacture.

Not only can the cup be made without special drel may be so coordinatedwith the continuousv feed of the paper that no attachmentsare necessaryto see that the paper is fed to the proper position in the mandrelorbit. Thus, the paper may be fed continuously from a roll and as theleading edge reaches the position shown in Figure 1, it will be pickedup by the mandrel and the mandrel itself rolling over the paper willstop the forward motion of the paper, causing it to pile up slightlyahead of the mandrel, but as soon as the severing operation is completedthe paper will immediately advance and be in position for the next swingof the mandrel through its orbit. No intermittent feed of the paperstrip is necessary because the formation of the cups is automaticallytaken care of by coordiation of the rotating mandrel with the continuousfeed.

The invention is particularly applicable to the manufacture of papercups from a continuous strip where the cup is formed on the end of thestrip and simultaneously severed as it is being wound, thereby avoidingthe separate formation and handling of blanks. This is possible byvirtue of the fact that the end portion of the strip retains its samerelative position with respect to the remainder of the strip as itis'being wound. The invention can also be employed, however, in cupforming operations where a blank is first formed. In this instance, theslit is made as already described in the forward edge of the blank whichmay be straight or curved. The

blank may be severed transversely from a strip already containing theslits at predetermined intervals, or the blanks may be formed and thenslit. Other materials besides paper may be employed, for example,regenerated cellulose, cellulose acetate, etc.

Certain other types of cups have heretofore been made from blanks havinga cut or line of severance extending to the apex point of the cup butthis type of cut or line of" severeance would defeat the purpose of thisinvention. It is important for the purpose of this invention that theout or line of severance terminate in the body of the blank therebycausing the formation of a reverse crease between the point oftermination of the cut and the apex point, as distinguished, forexample, from Hutt et al., U. S. Patent 2,114,470, where the line ofseverance terminates below the apex point and is primarily for thepurpose of forming an overlapping shoulder. A reverse crease or flap isformed not between the interior point of termination of the cut and theapex point, as in the present invention, but between the apex point anda side edge. The method described in the aforesaid patent does not lenditself to the formation of cups on the end of a continuous strip.Furthermore, it is of outstanding importance in the present inventionthat the reverse flap caused by the cut in the edge of the material besealed to the face portion of the material as the cup is'wound, whereasthe flap or wing in the above mentioned patent is said to be provided toprevent slippage and is not sealed to the blank.

This application is a division of my co-pending application Serial No.272,080, filed May 6, 1939, which is directed more particularly toward amethod or process of making cone-shaped vessels having a pointed apex,as herein disclosed.

Having thus described the invention, what I claim as new and desire tosecure by Letters Patent of the United States is:

1. A blank for forming cone-shaped paper cups having a pointed apex,comprising opposite curved sides of the same radius of curvature and twostraight parallel sides intersecting said curved sides, one of saidcurved sides being convex and the other concave with the center ofradius of curvature of the convex side within the blank and the concaveside having a slit therein at a point between the apex point and one ofthe straight sides, said slit terminating in the body of the blank andbeing so directed that a reverse crease is formed in the body of theblank between the point of interior termination of the slit and the apexpoint when the blank is wound into a cup.

2. A blank for forming cone-shaped paper cups having a pointed apex,comprising two opposite curved sides intersecting each other, one ofsaid sides being convex and the other concave with the same radius ofcurvature and with the center of radius of curvature of the convex sidewithin the blank, the concave side having a slit therein between theapex point and the point of intersection of the two sides, said slitterminating in the blank at a point separated from the apex point andbeing so directed that a reverse crease termediate between the apexpoint and the' straight side and so directed that a reverse crease isformed in the body of the blank between the point of interiortermination of the slit and the apex point when the blank is wound intoa cup.

4. A cone-shaped cup having a pointed apex formed from a blankcomprising sides of the same of curvature of the convex side as the apexpoint radius of curvature, one of said sides being convex and the otherconcave with the center 01 the radius of curvature of the convex sidewithin the blank and with a slit in the concave side terminating in theblank at a point separated from the apex point, said blank being woundaround the center of radius of curvature of the convex side as the apexpoint and said slit being so positioned that a reverse crease is formedin the body of the blank between the point of interior termination ofthe slit and the apex point thereby forming a flap and said flap beingsealed face to face with an overlapping portion or the blank.

5. A cone-shaped cup having a pointed apex formed from a blank,comprising opposite curved sides of the same radius of curvature and twostraight parallel sides intersecting the said curved sides, one of saidcurved sides being convex and the other concave, with the center of theradius of curvature of the convex side within the blank and with a slitin the concave side terminating in the blank at a point intermediatebetween the apex point and .one of the straight sides, said blank beingwound around the center of radius and said slit being so positioned thata reverse crease is formed in thebody of the blank between the point ofinterior termination of the slit and the apex point.

6. A cone-shaped cup of substantially true conical form wound from ablank, comprising two I curved sides and a straight side, one of saidcurved sides being convex and the other concave, with the center ofradius of curvature of the convex side within the blank and with a lineof severance in said concave side terminating in the blank at a pointintermediate between said center of radius of curvature of said convexside and the straight side, and so positioned that a reverse crease isformed in the body of the blank extending substantially between thepoint of interior RALPH G. AMBERG.

